Démare, already victorious in 2017 of what was once Paris-Brussels, beat Denmark's Tobias Lund Andresen and Belgium's Jordi Meeus in the sprint.
The three-time France champion (2014, 2017, 2020) was part of a group of 23 strikers that included other sprinters (Biniam Girmay, Bryan Coquard, Tom Van Asbroeck, Clément Venturini) but not the Belgian Tim Merlier, one of the favorites of the day.
Winner of the second stage of the Boucles de la Mayenne a week ago, the sprinter of the Groupama-FDJ formation signed in the shadow of the Stade Roi-Baudouin the second success of the season.
"I was not at my level at the beginning of the season," admitted the former Milan-Sanremo winner (2016). "But I'm building up the pressure. There, I feel that it's gone, "he added, probably to Marc Madiot, for a selection for the Tour de France he hopes to compete.
The manager of the Groupame-FDJ will have to decide when unveiling his selection for the Grande Boucle between a team totally devoted to its leader David Gaudu (4th in 2022) or a formation also aiming for stage victories in the sprint, with Démare therefore.
Perhaps motivated by his recent fatherhood - "I kiss my wife and my little Margaux", he said at the finish - the native of Beauvais (31) was attentive when the decisive breakaway took shape halfway through the race.
"It left very early, we had to be present. Especially on this new course more rugged than in the past," he explained before analyzing "a complicated sprint".
"I was in the wheel of Girmay, maybe a little far away when it threw to the 200 meters. But once in the lead I knew I was going to win," he said.
© 2023 AFP